107,994 research outputs found
Micro-Electro-Mechanical-Systems (MEMS) and Fluid Flows
The micromachining technology that emerged in the late 1980s can provide micron-sized sensors and actuators. These micro transducers are able to be integrated with signal conditioning and processing circuitry to form micro-electro-mechanical-systems (MEMS) that can perform real-time distributed control. This capability opens up a new territory for flow control research. On the other hand, surface effects dominate the fluid flowing through these miniature mechanical devices because of the large surface-to-volume ratio in micron-scale configurations. We need to reexamine the surface forces in the momentum equation. Owing to their smallness, gas flows experience large Knudsen numbers, and therefore boundary conditions need to be modified. Besides being an enabling technology, MEMS also provide many challenges for fundamental flow-science research
Counter operation in nonlinear micro-electro-mechanical resonators
This paper discusses a logical operation of multi-memories that consist of
coupled nonlinear micro-electro-mechanical systems (MEMS) resonators. A MEMS
resonator shows two coexisting stable states when nonlinear responses appear.
Previous studies addressed that a micro- or nano-electrical-mechanical
resonator can be utilized as a mechanical 1-bit memory or mechanical logic
gates. The next phase is the development of logic system with coupled
multi-resonators. From the viewpoint of application of nonlinear dynamics in
coupled MEMS resonators, we show the first experimental success of the
controlling nonlinear behavior as a 2-bit binary counter.Comment: 5 pages, 13 figure
Model of Electrostatic Actuated Deformable Mirror Using Strongly Coupled Electro-Mechanical Finite Element
The aim of this paper is to deal with multi-physics simulation of
micro-electro-mechanical systems (MEMS) based on an advanced numerical
methodology. MEMS are very small devices in which electric as well as
mechanical and fluid phenomena appear and interact. Because of their
microscopic scale, strong coupling effects arise between the different physical
fields, and some forces, which were negligible at macroscopic scale, have to be
taken into account. In order to accurately design such micro-electro-mechanical
systems, it is of primary importance to be able to handle the strong coupling
between the electric and the mechanical fields. In this paper, the finite
element method (FEM) is used to model the strong coupled electro-mechanical
interactions and to perform static and transient analyses taking into account
large mesh displacements. These analyses will be used to study the behaviour of
electrostatically actuated micro-mirrors.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Packaging of RF Mems Switching Functions on Alumina Substrate
Recently the strong demands in wireless communication requires expanding
development for the application of RF MEMS (Radio Frequency micro electro
mechanical systems) sensing devices such as micro-switches, tunable capacitors
because it offers lower power consumption, lower losses, higher linearity and
higher Q factors compared with conventional communications components. To
accelerate commercialisation of RF MEMS products, development for packaging
technologies is one of the most critical issues should be solved beforehand.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
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Natural convection heat transfer effects with micro finned structures
This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.Micro-scale natural convection plays an important role in heat removal from microelectronic components and Micro-Electro-Mechanical Systems (MEMS) devices. Natural convection of macrofin arrays has been extensively studied by many researchers over the past several decades; however analysis of free convection around microfin arrays is less well researched. The objective of this work was to experimentally investigate the effects of micro fin height and spacing for a horizontally mounted heat sink on heat transfer coefficient when operating under steady state natural convection conditions. An array of micro finned copper heat sinks was fabricated using micro-electro discharge wire machining (Ό-EDWM) with fin height ranging from 0.25 to 1.0mm and fin spacing from 0.5 to 1.0mm respectively. Results showed that values of the convective heat transfer coefficient increased with increased fin spacing and decreased as fin height increased.This study is funded by Advantage West Midlands (AWM)
DELAY DIFFERENTIAL EQUATIONS AND THEIR APPLICATION TO MICRO ELECTRO MECHANICAL SYSTEMS
Delay differential equations have a wide range of applications in engineering. This work is devoted to the analysis of delay Duffing equation, which plays a crucial role in modeling performance on demand Micro Electro Mechanical Systems (MEMS). We start with the stability analysis of a linear delay model. We also show that in certain cases the delay model can be efficiently approximated with a much simpler model without delay. We proceed with the analysis of a non-linear Duffing equation. This model is a significantly more complex mathematical model. For instance, the existence of a periodic solution for this equation is a highly nontrivial question, which was established by Struwe. The main result of this work is to establish the existence of a periodic solution to delay Duffing equation. The paper claimed to establish the existence of such solutions, however their argument is wrong. In this work we establish the existence of a periodic solution under the assumption that the delay is sufficiently small
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